Field of Invention
The present invention relates to the field of shock detectors. More specifically, the invention relates to a low-power shock detector and detection method for assessing shock damage.
Shock events may cause significant damage to equipment and structures such as stored military hardware, bridges, pipelines, tunnels, and buildings. In some structures, such as nuclear power plants and chemical plants, shock damage caused by an earthquake may cause critical damage that may lead to catastrophic consequences. Additionally, the readiness of stored military hardware has become more important as the complexity of the systems has increased because these sensitive systems must be stored for extended periods of time and yet be capable of performing when needed. However, environmental conditions such as excessive temperature and humidity and vibration of the military hardware during transport, storage, and deployment can cause deterioration and damage to the hardware.
Therefore, a method and device for assessing the energy imparted to the equipment or structure from a shock event is required so that any resulting damage may be detected, assessed, and repaired. The device must continually monitor for shock events that exceed a critical value, "critical shock events," and also assess the effects of less serious shock events for long periods without required detector maintenance. For example, sophisticated military hardware such as the Patriot missile requires continuous monitoring for periods in excess of seven years without maintenance to the detector.
Typically, the sophisticated military hardware uses mechanical critical shock indicators that, for example, use a vial that is broken or a ball held in place by springs that is displaced to indicate the magnitude of the shock event. A number of the mechanical detectors each set for different critical shock levels may be placed in series to allow detection of the magnitude of the shock. However, the mechanical indicators measure only the magnitude of the shock and do not account for the duration of the shock or extended, low-level shock events. Additionally, the mechanical indicators must be individually checked to determine whether a critical shock event has occurred.
Accordingly, a device for measuring the shock energy applied to a structure or equipment and that provides for remote monitoring of the shock is needed. Further, because equipment, such as military hardware, must be moved the monitoring device is preferably compact and mobile and is capable of operating for extended periods without maintenance. Thus, the detector preferably provides for low power consumption and includes a self contained energy source.